Purification of crude synthetic peptide mixtures often employs a multi-step chromatographic purification process. The first step removes most of the undesired components, followed by a different step to “polish” the material to the desired purity level. If applicable, a single step process can produce significant time and cost savings provided the single step can achieve the necessary purity while maintaining a desirable yield and throughput. A multistep process using the same stationary phase, can provide savings of time and costs.
The work presented here demonstrates the development of a multi-step purification process on a single stationary phase for a commercially significant crude synthetic peptide mixture, Exenatide (Figure 1.). The focus is on the initial development work, including the screening of multiple conditions to evaluate which steps will produce material of suitable purity. The investigated parameters include eluent pH, buffer components, and organic solvent composition.